CiRC. 139 



have a solid bed of flint four feet thick of a whitish-grey colour. Sometimes we 

 find small pockets with beautiful quartz crystals embedded. The blocks of Chert 

 as it is called are sent into the Potteries to grind other flinty and pottery 

 material for making china, etc. This formation of flint and its deposits is one of 

 the geological problems of the day ; yet even embedded in this hard flint he has 

 found fish teeth. 



Mr. William Gregson, F.G.S., writes that the district under consideration 

 embraces the eastern portion of one of the most charming of Yorkshire dales 

 and one which is exceedingly interesting from a geological point of view. The 

 Lower Magnesian Limestones which occupy the tract of country between Hedale 

 and Kilgram Bridge do not extend so far west as the latter place, which is generally 

 regarded as the eastern boundary of Wensleydale. Proceeding up the dale in a 

 westerly direction from the wooded slopes of Clifton Castle, we pass over the 

 alternating shales and sandstones of the Millstone Grit formation for five or six miles, 

 until we reach the higher beds of the Yoredale series in the neighbourhood of East 

 Witton, where the Main Limestone occurs with a thickness of 20 to 30 feet. Over- 

 looking the latter on the south-west, and towering to a height of some 1,500 feet, 

 stands the well-known and conspicuous landmark of Pen Hill, which is capped by 

 the Red Scar Grit, immediately overlying the numerous beds of shales and sand- 

 stones of the Lower Millstone Grit. West of this point, for several miles up the 

 ■dale, we have a remarkable development of the Yoredale Rocks, consisting of 

 several hundred feet of limestone, separated or interstratified by beds of sandstone 

 and bituminous plate of varying thickness, with occasionally thin seams of impure 

 ■coal. The charm which characterises the scenery of Wensleydale, and adds so 

 materially to the beauty of the landscape, undoubtedly arises, in some degree from 

 this want of uniformity, and the varied character of the Yoredale Rocks; for the 

 soft shales are being eroded and the hard limestones left to form pretty cataracts, 

 much in the same manner, and by a similar process (though of course on a smaller 

 scale), to that which is now in operation at the Falls of Niagara, in America, 

 where the limestone ledge is constantly being undermined by the erosion of the soft 

 shales beneath; thus causing the falls to be slowly but surely receding at an ever 

 varying speed, southwards towards Lake Erie. On the south-western side of Ley- 

 burn, and close to the town, a valuable bed of hard siliceous limestone known to 

 the commercial world as Chert, is now being worked by Mr. W. Home, F.G.S., 

 of Leyburn, and is extensively used in the manufacture of Staffordshire and other 

 wares. With few exceptions, the limestone beds around Leyburn dip to the south- 

 east at a slight angle, eventually disappearing beneath the rough grits of Masham 

 and Witton Moors. The rocks, both on the north and south banks of the River 

 Ure, are here overlaid by a post-glacial deposit of varying depth, forming river 

 terraces, upon which grow excellent crops of rich grass, turnips, etc. ; and here 

 also many of the celebrated Wensleydale cheeses are made. There are excellent 

 limestone quarries at Harmby and at Leyburn, some of which, being fairly fossil- 

 iferous, will well repay a visit from the members of the geological section. On the 

 village green at East Witton stands a huge boulder, weighing over three tons, 

 which is now used as a drinking fountain. 



ALTITUDES. — The following are the heights above sea level of various 

 points in Wensleydale : — 



Kilgram Bridge 



High Tervaulx ... ... 



East Witton Fell 



Ancient Camp (south of Middleham Castle) 



Leyburn Station 



Leyburn Shawl ... ... ... over 



Pen Hill Beacon 



BOTANY. —On this occasion the botanists have the unusual advantage of a 

 virgin field for exploration, as there do not appear to be any published records for 

 the immediate neighbourhood of Jervaulx Abbey, not even in Baker's ' North 



